The membrane electrode assembly (MEA) mainly has two catalyst layers (i.e. anode and cathode) isolated by a solid polymer electrolyte membrane (i.e. proton exchange membrane) and gas diffusion layers respectively attached to the outsides of the two catalyst layers. A bipolar plate having a fluid channel is on the outside of the gas diffusion layer. When continuously replenishing hydrogen to the anode and continuously replenishing oxygen or air to the cathode, an oxidation-reduction reaction may occur on the electrodes, wherein the protons arrive at the cathode via the electrolyte and the electrons arrive at the cathode from the anode via an external load so as to complete the current loop. The reaction product (water) and unreacted hydrogen and oxygen or air are discharged from the gas channel outlet.
During the assembly of the fuel cell, each element (such as the end plates, collector plates, monopolar plates, and bipolar plates) is sequentially stacked. To ensure the reaction gas introduced in the battery can smoothly flow inside the battery without leaking, many sealing members (e.g. gas sealing members and cooling flow field sealing members) are added between each of the elements, and the object of sealing is achieved by the specific placements of the sealing members and the lamination between the elements. However, as the power of the battery is increased, since the quantity of the elements is increased, assembly error inevitably occurs, and the error affects the effectiveness of the sealing members and may even cause sealing failure.